fn main() {
    let container;
    {
        let test_val = true;
        // ----------- 错误演示 --------------
        // container = &test_val;
        // ----------- 正确演示 --------------
        container = test_val.clone();
    }
    println!("{}", container);
    // ----------- lambda函数 ------------
    let f = |x| -> u16 {
        x
    };
    println!("{}", f(10));
}
